In motor vehicles which are electrically driven, in particular electric vehicles and hybrid electric vehicles, secondary batteries are used, in particular, in order to supply electrical energy to electrical drive devices of the motor vehicle by means of a vehicle-end electrical power supply system by way of said secondary batteries. The secondary batteries are usually in the form of lithium-ion secondary batteries. In addition to individual battery cells, a conventional secondary battery has a large number of electrical components which can be arranged, for example, in a housing of the secondary battery.
Contactors which form part of a so-called “Battery Disconnect Unit” (BDU) are provided in order to connect the secondary batteries to the electrical power supply systems and, respectively, to disconnect secondary batteries, which are connected to the electrical power supply systems, from the electrical power supply systems. A BDU of this kind is known, for example, from WO 2009/001086 A2.
Laid-open specification DE 100 21 811 A1 relates to a removal-prevention means for electronic components of an electronic operating system, which is installed in a motor vehicle, for operating the motor vehicle. The components which are installed in the motor vehicle are connected to one another by means of at least one data line, wherein each component is authorized by the manufacturer to operate in a specific operating system, wherein each component contains an identification code, which is individualized for this specific operating system, in a memory. The identification codes of the components are compared at least for starting the vehicle, wherein each component sends identification signals, which are correlated with the identification code of said component, to the other component and/or receives identification signals from the other components. In this case, the operating system is designed such that it allows proper operation of the vehicle only when all of the components have the same identification code.
Laid-open specification DE 10 2008 021 542 A1 discloses a monitoring apparatus for contact or access protection of a hybrid vehicle, comprising a number of high-voltage components and comprising an electronic control unit which is connected to a low-voltage on-board electrical system battery, the power actuators of the said electronic control unit being connected to a high-voltage battery by means of a circuit breaker and driving at least one electrical machine. The high-voltage components are monitored by means of a line loop and are deactivated when the line loop is open, wherein a magnetic field-sensitive sensor of a releasable contact connection of the electrical machine or of the electronic control unit is connected to the line loop, and wherein a control module of the electronic control unit activates a discharge unit for discharging an energy store in an electric shock-proof manner depending on a sensor signal which is generated when the contact connection is released from the sensor.
Laid-open specification DE 10 2011 003 082 A1 discloses a system for high-voltage disconnection in a vehicle having at least two high voltage-carrying components, each component having a housing, at least one connection element for a data bus and at least one connection element for a high-voltage supply, wherein each high voltage-carrying component is designed to locally detect an event, which event is intended to trigger high-voltage disconnection, characterized in that each high voltage-carrying component is locally designed to trigger high-voltage disconnection of the high voltage-carrying component in response to the detection of the event. As an advantageous embodiment, access to components which are at a dangerous voltage is possible only after a connection element of the data bus has been removed, the removal or disruption of said connection element leading to rapid disconnection of the electrical system.
Replacement of individual electrical components of a secondary battery by laypersons can lead to environmental damage and/or to a defect. This damage can occur directly, for example by a flashover, or only over the course of time during operation of a secondary battery, for example by long-term overloading of a battery cell.